Those look terrible lol. I'm curious to see how the car does now that they are clean.
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Cranks but won't start
- Thread starter e9coupe
- Start date
I was glad to see bad numbers. I have plans tonight and almost feel like canceling just to test the injectors in the car.
Got the injectors in. Still runs like shite! Yippee. I have a fuel pressure gauge on the way to check pressure but... WTH.
Check the pressure to rule it out; but, sad to say it is probably time to revisit the valve timing.
I'm with @Old Guy. It really doesn't sound like a fuel issue, it is possible though unlikely.
Despite your leak down results I'd check the indexing of the crank and cams. Make double sure the crank is not 180 out of phase.
You can keep your gauge hooked up to the port on the fuel filter. Depending on tool config, if it has a long hose, you might consider taping it to the back window so you can watch what is going on from inside the car.
Verify your crank angle sensor. You might have to get "middle school" on it and get a data logging setup. MotorMouth has published a way to get/watch real time data.
Despite your leak down results I'd check the indexing of the crank and cams. Make double sure the crank is not 180 out of phase.
You can keep your gauge hooked up to the port on the fuel filter. Depending on tool config, if it has a long hose, you might consider taping it to the back window so you can watch what is going on from inside the car.
Verify your crank angle sensor. You might have to get "middle school" on it and get a data logging setup. MotorMouth has published a way to get/watch real time data.
To recap recent events... the motor was running decent but had the roughness that kind of showed in the video. I took it for a drive up and down the street and it ran the same in first gear and not under load. The first time I accelerated hard the motor misfired way worse, like it does now, and now misfires badly with or without load.
Since then I've rechecked timing marks, done a leak down, compression test (since I was already there), had the injectors cleaned/calibrated and made sure the battery cables were clean and connected well.
Heavy misfiring after a load could be fuel but I usually go to ignition first. There are six new coils and plugs, ignitor has been replaced and a friend probed the signals from the ECU on his hand scope and said it looked good. I'll look into the crank angle sensor procedure.
Since then I've rechecked timing marks, done a leak down, compression test (since I was already there), had the injectors cleaned/calibrated and made sure the battery cables were clean and connected well.
Heavy misfiring after a load could be fuel but I usually go to ignition first. There are six new coils and plugs, ignitor has been replaced and a friend probed the signals from the ECU on his hand scope and said it looked good. I'll look into the crank angle sensor procedure.
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If you are absolutely 100% confident that the valve timing is not an issue then I would check the base ignition timing as per the service manual.
You can get tail pipe adapters for O2 sensors which allow you to sample on the go with a wide band sensor. Doing that might give you some idea as to whether you are having a fueling issue of some kind. You can also measure the voltage that that your existing narrow band sensors are reading; but, narrow band sensors are so no linear that it pretty much just tells you that you are above 14.7 or you are below 14.7. It would point out differences between the front and rear banks and would probably tell you whether you were really really lean.
You can get tail pipe adapters for O2 sensors which allow you to sample on the go with a wide band sensor. Doing that might give you some idea as to whether you are having a fueling issue of some kind. You can also measure the voltage that that your existing narrow band sensors are reading; but, narrow band sensors are so no linear that it pretty much just tells you that you are above 14.7 or you are below 14.7. It would point out differences between the front and rear banks and would probably tell you whether you were really really lean.
I have test pipes with an O2 sensor bung and a LM-1 for situations like this. This [prior to having kids] was part of my test rig for my CTSC.
This looks to be modern version as all my tools are now vintage.
www.innovatemotorsports.com
FYI, Legend injectors look the same as NSX but run super lean. I tried them initially when getting my original injectors cleaned and the NSX was my daily driver. I didn't get past the idle stage and just borrowed until my original injectors came back from RC.
This looks to be modern version as all my tools are now vintage.
LM-2: Handheld Digital Wideband Air/Fuel Ratio Meter & Datalogger, Single O2, Complete Kit
LM-2 AFR Kit w/case
www.innovatemotorsports.com
FYI, Legend injectors look the same as NSX but run super lean. I tried them initially when getting my original injectors cleaned and the NSX was my daily driver. I didn't get past the idle stage and just borrowed until my original injectors came back from RC.
This was the tail pipe adapter thing that I was thinking of which allows you to use any wide band sensor for tail pipe AFR measurements. Some of the tips on the NSX exhaust system that really flare out wide may render the adapter ineffective.
